A screenshot can show you how an edition is presented, but it is not automatically a sample of the files a buyer receives. Before choosing a downloadable collection, separate what the promotional image lets you observe from what the delivery description actually specifies.
This distinction does not imply that the product is poor or that the screenshot is deceptive. It prevents a limited piece of evidence from answering a different question. A visible page layout and a delivered image file are not the same object of comparison.
Identify what the sample actually is
Look for a description of the sample: a page capture, a thumbnail, a cropped detail or a downloadable example. If the format is not identified and delivery characteristics matter to you, that uncertainty should remain on your purchase note.
Imagine a fictional listing displaying three screenshots of a gallery page. They establish that the edition includes captions and a particular arrangement of images. They do not, by themselves, establish the dimensions, file format or completeness of a download package that is mentioned elsewhere.
You can still judge aspects of the photographic proposal visible in the sample. What you should not do is quietly transfer every impression of the screenshot to a different file you have not inspected.
Use an evidence ladder
At the first level, write what you can directly see: layout, image selection, readable text or a visible crop. At the second, note what the offer explicitly says about delivery. At the third, list anything you would otherwise be guessing.
A completed example could read: “Visible: the sequence pairs portraits with rooms. Described: a download is available separately. Unknown: whether that download contains individual photographs, a page-based edition or both.” The missing fact concerns the nature of the product, not a subjective judgment about sharpness.
If a technical characteristic is decisive for your intended use, ask for a clear specification or an appropriate sample that the publisher is willing to provide. Do not invent compatibility or quality guarantees from a promotional capture.
Keep aesthetic and delivery decisions connected but separate
You might already know you want the work, while remaining uncertain about which format to purchase. That is different from being unconvinced by the photographs themselves. The next question should address the actual gap.
Conversely, a detailed file specification cannot create an interest in the images that you do not feel. A technically described package can still be the wrong collection for your taste.
The final note might say: “I want this sequence; I need to clarify the downloaded edition before choosing that option.” This lets the sample do its proper work as an introduction while reserving delivery judgments for evidence about delivery. You are buying a defined product, not the assumption that every image shown in an advertisement represents the file that will arrive.